AIMTo investigate the correlation between the gastric adaptive cytoprotection and the low concentration alcohol intake in a chronic drinking rat model and the effect of chronic ethanol exposures on the cell turnover of the gastric mucosa and its possible role in adaptive cytoprotection.

METHODSSprague-Dawley rats received the drinking water containing 6% (v/v) ethanol as their only water intake for 28 days. In the different stages of the 28 days (1st, 3rd, 7th, 14th and 28th days), the stomachs of the rats were cannulated and perfused with pure ethanol, and the severity of mucosal lesions was measured in 2 hours at the end of perfusion respectively. The cell proliferation and apoptosis in gastric mucosa of rats in different groups were analyzed by flow cytometer, immunohistochemistry and computer image analysis.

RESULTSPure ethanol caused ulcer and haemorrhagic damage in the corpus and antral mucosa of the control rats. These lesions were prevented by pretreatment of the animals with ethanol exposure in the 3 rd to 14 th days. The damage index was decreased by 80%, as compared with those in control rats. There was no significant difference in the rats exposed to the ethanol in the 1st and 28th days. Compared with control, the cell apoptosis in gastric mucosa of the rats was enhanced during they exposure to the ethanol in the 3rd to 28th days. Otherwise the cell proliferation was increased in the 3rd to 28th days, and decreased in the 28th days, respectively.

CONCLUSIONChronic adequate alcohol intake may enhance the cell turnover of gastric mucosa and lead to an adaptive cytoprotection. Long-term stimulus with the low concentration ethanol may cause the atrophy of gastric mucosa and reduce the gastric mucosal cytoprotective effect.